| Summary: | 碩士 === 國立臺灣大學 === 電信工程學研究所 === 106 === This paper presents the design of a 3.3-GHz omnidirectional phased array antenna system with 16 subarrays for circularly beam scanning, which is suitable for fixed point or on-vehicle detection applications. Each subarray consists of four balanced reflector dipoles, microstrip transmission lines, and a four-way Wilkinson power divider. After the implementation of subarray antennas and 3-D printing mechanical assemblies, the circular array phase-compensated gain is 16.3-dB. The beam-switching control module of this array system feeds four contiguous subarray each time in a sequential manner. This module consists of FR4 substrate, SPDT, SP4T, SP8T switch chips that connected via coplanar waveguides. The digital pins of various chips are connected to PCB header connectors near the edge of the board, and the digital signal controller gives them either high or low voltage corresponding to the operation states. A passive full duplex circuit which exploiting 180-degree hybrids and ring hybrid couplers achieves 32-dB isolation between transmitter and receiver, and provides signal paths for digital monopulse processing. The measurement of the phase-shift control module shows desired result of all 64-bit states for eight channels. This module gives the finer beam-stirring angular increment. The verification of software-defined radio transceiver module shows it ability to take control of the waveforms by selecting appropriate RF system parameters.
|
|---|
